Foster performed heroics on his Red Devils debut against Derby last weekend but made way for Tomasz Kuszczak for Wednesday’s Old Trafford victory over Bolton.

There have been suggestions that Barnsley may try to sign the 24-year-old Foster on loan in time for their FA Cup semi-final against Cardiff if the Tykes cannot re-sign Luke Steele on loan from West Brom.

Ferguson said the reason he had recalled Kuszczak after a suspension was because the Polish keeper is eligible for the upcoming Champions League games and Foster is not. That could prove crucial with Edwin van der Sar nursing a groin injury.

The United manager said: “The reason he did not play is quite simply this: Ben is not registered for Europe.

“He could have felt he was entitled to play, and expected to play, but that would have meant it was a blow for Tomasz Kuszczak, so really we had to bring Tomasz in because of the European situation.

“But we have to make a decision about whether Ben should go on loan now. Edwin’s had this groin injury two or three times this season so we could end up a little short. I’m going to sit down with Ben and discuss it with him.”

Ferguson revealed his reshuffled defence against Bolton was a pre-emptive experiment in case Rio Ferdinand misses Sunday's clash with Liverpool.

The England defender continues to carry a slight back injury and, with the Merseysiders' visit to Old Trafford looming large, Ferguson opted to rest Patrice Evra and Wes Brown, fielding a defence of Owen Hargreaves, Nemanja Vidic, Gerard Pique and John O'Shea.

The manager said: "We wanted to rest Wes Brown in case Rio doesn’t make it, then we’ve got the alternative of playing Wes at centre-back – that’s a decision we’ll have to make.

"We tried Owen Hargreaves at right-back, and we can play John O’Shea there on Sunday and bring Patrice Evra in. It’s important to do these things simply because of Rio’s injury."

Meanwhile, United have appointed former captain Bryan Robson as an ambassador for the club.

Robson, the former England midfielder who went on to manage Middlesbrough, Bradford, West Brom and Sheffield United, will help the club to promote their commercial and charitable arms, working alongside United director Sir Bobby Charlton.

Robson, who will work as a club ambassador an initial 12-month period, said: “Since signing for the club in 1981, it has always been special to me.

“I enjoyed the happiest and most memorable times of my career at Old Trafford and it will be great to play a role in making the club even more successful.”

United chief executive David Gill said: “Bryan Robson was the outstanding player of his generation.”